Further analysis of last Sunday's tsunami in New Zealand shows waves of almost two metres reached the port of Lyttelton.
The National Institute for Water & Atmospheric Research says there were about six locations around New Zealand where waves were higher than a metre, causing strong currents.
Principal scientist Rob Bell says Lyttelton would have faired badly if it had been high tide, as the largest waves of 1.9 metres came in.
Dr Bell says the waves arrived in two hour cycles causing a sloshing effect in Pegasus Bay, north of the port.
Gisborne had the second highest wave, at 1.7 metres.
The tsunami in New Zealand was triggered by a magnitude 8.8 earthquake at 3.34am on Saturday in Chile.
Harbour tides
Canterbury Regional Council says the tsunami caused significant tidal changes in Lyttelton harbour for two days.
Tidal currents in the harbour normally flow at one to two knots.
However, navigation safety manager Evan Walker says currents flowed at five to six knots for at least 48 hours afterwards.
